Messenger - Vol. 2, No. 3, Page 10
Summer 1993
On Research
Some young female skaters are landing on "old" bones
When Michelle Provost-Craig, assistant professor of sports science at
the University of Delaware, undertook a study of female figure skaters, she
found some of these highly trained, young athletes had the bone density of
post-menopausal women.
"This sport requires an early commitment, even a pediatric one,
because skaters may start as early as the age of 5. It requires long
training hours, up to five hours a day, and maintenance of low body weight.
It is a situation that sets women up for eating disorders and the
possibility of lowered bone density," Provost-Craig says.
The researcher followed 10 competitive athletes of roughly the same
height and weight, all of whom exercise heavily and eat lightly. The
preliminary study, one of the first of its type, examined energy
expenditure while resting, bone mineral density and percentage of body fat.
In a February presentation before the American College of Sports Medicine's
mid-Atlantic district, Provost-Craig reported that three of five skaters
followed in the bone mineral density study had lowered density for their
age and gender.
"It's chilling when you think about how these kids with those bones
are thrown up in the air and land on a blade one-eighth of an inch thick,"
she says. "It's amazing they don't get more fractures."
The athletes' bone mineral density was measured by a CAT scan of the
lower spine, under the direction of Dr. Theodore Harke at the A.I. du Pont
Institute, a children's hospital in Wilmington, Del. One of the skaters, at
age 17, had a reading of 135 millimeters per cubic centimeter, whereas, the
average for her age and gender is 204.
According to Provost-Craig and Harke, this preliminary bone density
study raises several questions. Are these young skaters at greater risk of
fracture now because they have the bones of 70-year-old women? Will the
bones with lower mineral density correct themselves over time, as happened
in the case of one competitive skater? And, as these young women give up
competition and go on with their lives, will they be at any long-term risk?
"Most of the data we have on lower bone density is on post-menopausal
women," Harke says, "so we don't know if the risk factor is the same for
these young athletes. And, as yet, we have no long-term data to indicate
that those with lower bone density levels will develop some sort of spine
problems within a few years after training."
Provost-Craig says the almost obsessive desire for a low body weight
by the skaters is documented in an eating attitudes survey taken by a
master's degree candidate in sports medicine. According to the survey by
Ann Rucinski, the caloric intake of female skaters is about 55 percent of
the recommended dietary allowance, or about 800-1,000 calories per day.
Seventy-eight percent of the 23 skaters interviewed said they were
terrified of becoming overweight, 65 percent wanted to be thinner and 48
percent scored in the anorexic range in eating attitudes.
"This attitude toward eating may mean these skaters have tendencies
toward anorexia, in which a misconception of body image leads to
self-starvation," Provost-Craig says.
To determine the percentage of body fat among these elite female
skaters, Provost-Craig used a hydrostatic weighing tank. Compared to a
normal college-age person who has 23.9 percent body fat, the skaters had an
average of 13.4 percent.
"This percentage of body fat is common with people who have to move
their bodies through space and whose performance, in part, is judged on
appearance," says Provost-Craig. "Gymnasts have 11 to 14 percent; marathon
runners, 11.4 percent; and dancers, 14.1 percent."
When the Delaware researcher checked the resting energy expenditure of
the skaters, she found their levels to be 3 to 30 percent lower than
average. "I think they become fuel-efficient," she says. "Just as a
fine-tuned car can go a lot further on a tank of gas, these kids can go
further on fewer calories than most."
Provost-Craig says her early research results underscore the perils of
trying to succeed in a sport. "The definition of what is aesthetically
pleasing must be redefined to include the word healthy," she says.
-Cornelia Weil